R-56 Ukrainian heavy-lift orbital launch vehicle. The R-56 was Yangel's ultimate superbooster design. Trade studies begun in 1962 resulted in a conventional tandem stage design capable of being transported on the Soviet canal system from the factory to the launch site, while still placing 40 metric tons into low earth orbit. However various Soviet government factions favored the much larger (and less practical) Korolev N1 or Chelomei UR-700 designs. Yangel made one last attempt to convince the government to sponsor a common approach to the lunar program, with different design bureaus concentrating on just one part of the mission, as the American's were doing. But his practical solutions obtained no traction, and further work on the R-56 was abandoned. More...

Associated Propellants

N2O4/Aerozine-50 Nitrogen tetroxide became the storable liquid propellant of choice from the late 1950's. Aerozine was a 50-50 mixture of hydrazine and UDMH developed for use in the Titan 2 missile. Copied in one Russian missile but otherwise straight UDMH used more commonly. Higher boiling point than UDMH. More...